Commit c81a748e authored by Paul E. McKenney's avatar Paul E. McKenney
Browse files

sh: Emulate one-byte cmpxchg 



Use the new cmpxchg_emu_u8() to emulate one-byte cmpxchg() on sh.

[ paulmck: Drop two-byte support per Arnd Bergmann feedback. ]
[ paulmck: Apply feedback from Naresh Kamboju. ]
[ Apply Geert Uytterhoeven feedback. ]

Signed-off-by: default avatarPaul E. McKenney <paulmck@kernel.org>
Cc: Andi Shyti <andi.shyti@linux.intel.com>
Cc: Palmer Dabbelt <palmer@rivosinc.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: <linux-sh@vger.kernel.org>
Acked-by: default avatarJohn Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
parent f2519d4d

arch/sh/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -14,6 +14,7 @@ config SUPERH 
	select ARCH_HIBERNATION_POSSIBLE if MMU

	select ARCH_MIGHT_HAVE_PC_PARPORT

	select ARCH_WANT_IPC_PARSE_VERSION

	select ARCH_NEED_CMPXCHG_1_EMU

	select CPU_NO_EFFICIENT_FFS

	select DMA_DECLARE_COHERENT

	select GENERIC_ATOMIC64

arch/sh/include/asm/cmpxchg.h

+3 −0
Original line number Diff line number Diff line
@@ -9,6 +9,7 @@ 


#include <linux/compiler.h>

#include <linux/types.h>

#include <linux/cmpxchg-emu.h>



#if defined(CONFIG_GUSA_RB)

#include <asm/cmpxchg-grb.h>
@@ -56,6 +57,8 @@ static inline unsigned long __cmpxchg(volatile void * ptr, unsigned long old, 
		unsigned long new, int size)

{

	switch (size) {

	case 1:

		return cmpxchg_emu_u8(ptr, old, new);

	case 4:

		return __cmpxchg_u32(ptr, old, new);

	}